As an insulator of a capacitor, SiO2/Si3N4 based dielectric materials have generally been used. The capacitor may be categorized in accordance with the type of electrode material used, such as a poly/insulator/poly (PIP) capacitor or a metal/insulator/metal (MIM) capacitor.
A thin film type capacitor such as the PIP capacitor or the MIM capacitor does not correlate to a bias, unlike a metal oxide semiconductor (MOS) capacitor or a junction capacitor. Therefore, thin film type capacitors have mainly been used for an analog product requiring a precision capacitor.
When compared to the PIP capacitor, the MIM capacitor has a disadvantage in that it is difficult to increase the capacitance per a unit area. However, the MIM capacitor exhibits better characteristics in terms of voltage coefficient of capacitance (VCC) and temperature coefficient of capacitance (TCC), and thus, is suitable for manufacture in a precision analog device.
As integration of semiconductor devices increase, a metal/insulator/semiconductor (MIS) capacitor cannot obtain desired capacitance due to a low insulator being formed between an insulator and a polysilicon film. Accordingly, there is an ever increasing demand for the MIM capacitor to replace the MIS capacitor.
Capacitors using silicon oxide (SiO2) or silicon nitride (SiN) insulators are popular, and may be produced using plasma enhanced chemical vapor deposition (PECVD). A capacitance density of about 1 fF/um2 can be obtained using such insulators.
Development of semiconductor technology has required increased integration and operation speed. In order to meet such demands, a need exists for material development and finer process technology. For semiconductor devices of 90 nm or less, a semiconductor device having increased operation speed can be manufactured by reducing an RC delay using black diamond (BD) having k˜2.9 and SiC, which is a low-K material.
However, in a process for forming the MIM, a problem may occur due to the use of a dielectric material made of a black-diamond material as an inter-metal dielectric (IMD) film. As illustrated in example FIG. 1, occurrence of a lifting phenomenon due to large stress differences between tantalum (Ta) that is a copper (Cu) barrier material and silicon nitride (SiN) that is an MIM insulator material used as a semiconductor wiring and a MIM flat panel and a BD material used as the inter-metal dielectric material so that adhesion between the inter-metal dielectric film and the insulator is degraded. Furthermore, the BD may raise the degradation phenomenon of the adhesion in a dry etch and a copper planarization process to increase the lifting phenomenon, having a large effect on the degradation of the reliability and yield of the device.